Typewriting machine having selective circuit closing means, including a conductive power roller



March 16, 1954 E. J. RABENDA TYPEWRIIINC MACHINE HAVING sELECTIvECIRCUIT CLosIN MEANS, INCLUDING A CoNDUCTIvE POWER ROLLER Filed Deo. 29,195o Snoentor E.J.RABENDA d (Ittomeg lll Egzz. um-

Patented Mar. 16, 1954 TYPEWRITING MACHINE HAVING SELEC- TIVE CIRCUITCLOSING MEANS, INCLUD- ING A CONDUCTIVE POWER ROLLER Edward J. Rabenda,Poughkeepsie, N. Y., assignor to International Business MachinesCorporation, New York, N. Y., a corporation of New York f ApplicationDecember 29, 1950, Serial No. 203,378

17 Claims. (Cl. 197-5) This invention relates to typewriting machines.

An object of the present invention is to provide an improved selectivecircuit closing means suitable for use in typewriting machines to enablesuch machines to remotely control other apparatus.

An object is to provide a circuit closing means which requires only avery small amount of additional space in the typewriting machine therebyenabling the machine to be made more compact or allowing for theinstallation of auxiliary mechanism or apparatus without increasing thesize of the machine.

An object is to provide a selective circuit closing means which does notimpose any appreciable additional loads on the mechanisms of the machineover their normal loads.

An object is to provide a circuit closing means which takes advantage ofalready existing parts in the machine as a means of selectively closingcircuits to thereby eliminate the necessity for providing a large numberof additional parts for the purpose of exercising the circuit closingfunction.

An object is to provide a simple and effective selective circuit closingmeans which is especially useful in power operated typewriters toenable, for instance, the control by such a typewriter of an auxiliarymachine such as a, tape punch or card punch.

An object is to provide a selective contact I means which requires veryfew additional parts over the normal number of parts incidental to thetype bar operating mechanism of a power operated typewriter.

An object is to provide a selective contact means in which a veryhighcontact pressure can be obtained without imposing any additionalload on the power mechanisms of the typewriter.

Another object is to provide a selective contact means for poweroperated typewriters which makes use of the normal parts of the powermechanism to close the selective circuits rather than axiliary partsoperated thereby so as to insure that the circuits actually will beclosed when the type bars are operated and not remain dependent uponadditional parts which may break, get out of timing, or not operate atall.

Other objects of the invention will be pointed out in the followingdescription and claims and illustrated in the accompanying drawings,which disclose, by wayof example, the principle of the invention and thebest mode, which has been contemplated, of applying that principle. *Inthe drawings:

Fig. 1 is a vertical section showing the inven tion as applied to apower operated typewriter.

Fig. 2 is a detail view in profile of one of the operating cams.

Fig. 3 is a bottom plan view of the cam shown in Fig. 2.

Fig. 4 is similar to Fig. 2 and shows a modified form of the cam whichenables the contact mechanism for a single key to initiate a successionof impulses.

Fig. 5 is a diagram showing how the contact plates of the cams may bewired to control auxiliary apparatus in accordance with a conventional2-hole combinational code.

The invention is disclosed in the drawings as applied to a well knownform of electrically driven power-operated typewriting machine knowncommercially as the IBM Electric, the power mechanism of which isdisclosed in Patent No. 2,506,444. It will be understood, however, thatthe invention is not limited to embodiment in a typewriter of the formillustrated but may be embodied in other typewriters by suitablemodifications of the power operating devices for the type bars and otherinstrumentalities of the typewriting machine. Y

Since the power mechanism is now well known in the art only a very briefdescription thereof will be given, The type bars, illustrated by thesingle type bar I0 in Fig. 1, are actuated by electric motive powerunder control of character keys Il, which are pivoted on a cross rod l2and restored by means of the springs i3. The power means includes, foreach separate type bar lll and its character key Il, a power unit havinga sublever I4 pivoted at i511 on an adjustable fulcrum member l 5 whichis suitably mounted in a frame 15b. The sub-levers i4 are retained inpivotal engagement with the fulcrum members I5 by means of springs I6which urge the sub-levers i4 in a counterclockwise direction so as totend to restore the type bars I0. Links I1 connect sub-levers I4 to typebars l0. The latter are pivotally mounted in a well known way on acurved fulcrum wire I8 inthe usual segment.

Pivotedat Illa on the sub-levers I4 are the operating cams l 9 which, inthe present caseare modiiied to enable them to function as circuitclosing devices. vThe sub-levers i 4 are provided with interposers 20which are pivotally slidably mounted at Mb on extensions Vof thesublevers I4 and are urged to the left by means of the springs 2| whichare anchored to lugs formed inthe sub-levers4 1 4 and to lugs at theright-hand ends of the interposers 20. The springs 2'l hold 3 theinterposers 20 in their left-hand positions with bent-over lugs 25athereof directly under neath lugs l I a formed in the keys l i.

The cams I9 are urged in a counterclockwise direction by springs `..22to ...engage extensions thereof `lvvith fbent-.over lugs`20b -formed *inthe interposers 20.

When any key Il is depressed, the interposer 20 therefor is depressedand thereby the corresponding cam I9 is urged @clockwise .until thetread of the cam engages l'the Ipower vroller PR which rotates in thedirectionof the arrow 4(ig. 1). The tread is eccentric,withfrespecttopivot Ma, consequently the rotation of the `cam will urgethe pivot Ma of the :cam fto :the right .-and i rock the sub-lever in aclockwise direction to actuate the related type barto .theprintingposition. Subsequently, the extension 19a of the cam will strike anadjustable finger I23 and, 4by

sliding along said finger, effect the positive disf engagement voi"r4the cam .13 ifrom :the power, roller The.. foregoing mechanism is`well ,known in the art and fully described in the above Vpatent in@greater detail.

For the purpose of effecting selective rclosure of rcircuitswhich rarerepresentative of the-.type

`.bars .and ;oth er instrumentalities which are operated,..the powerroller :PR is provided .with :a

sleeve of so-called conductive rubber instead of the `.usual frubbersleeve `and the :cams :I 9, instead -.o f,.being .molded of a `single.piece of plastic, or made cfa snglefpiece-oimetal, arearranged toprovide two contact .shoes vwhich-will be-electri- ,cally connected ,byA.the @conductive rrubber sleeve `when .the camds yfeng-aged with thepower-roller BR.

Theconstruction of acam 'I9 ,is shown .in Figs. :zand `3-in .which thebody of the ,cam visemade of ,an .insulating material lsuch y as moldednylon, to

.the ;sides ,of Y.which are .securedin any Asuitable `.way .the.electrically conductive contact plates Mb.V These contact ,plates areinsulated from -,eachiotherby the .body'of the camfand the lefthandedges thereof .are shaped .to .form with the body I9 a continuous treadsurface which-is `de Signed-tto y.roll .over the .surface of lthepowerroller BR. .when the-cam .is engagedtherewith, .as dey,scribed above.

When operated in this ifashion, theconductive yrubber will establish yanelectrical Aconnection ,between the contact :plates [9b and Ait only-remains to provide `a means nof `connecting thel .plates ,isb toexternal :control circuits which Ameans lnaturally must remain effectivewhile the ycam `|f9 .isin .motion during the .operating cycle .of thetype Thismeans may lconvenienl'fly -take Vthe form `of very weak,metallic `springs vor Lequivalent Iflexible `for .resilientelectrically -con- .-duclve `.members 24 which :are hooked :intoholes Icin the ,-plates. The .bodyfof -the cam I9 is cut Vaway `as show-n -inFig. 3 adjacent the holes i90 may then be madeof metal. The -pair ofvsprings `2A associated with -each ycam provide a `means of .conductingcurrent `from external `circuits .to .the

plates 19h. n

In order .to .function .esa .circuit `.closing device,

it is necessary that only one plate I9b be provided for each cam I9.However, the wear on the tread surface of the cam will be more evenlydistributed if the cams are provided with two plates with `theinsulating material ffsandwiched JPR, thereisprovided a common brush CB(Fig.

`1) whichfmayfbear on the surface of the rubber fcronwa metalliezbandassociated with the power roller and electrically connected with theconductive sleeve.

vIn Fig."5, there is shown how the electric con- ;nections are made tothe power roller and the conducting plates i9b to enable the typewriterto 4control .anwauxiliary machinefsuchras, :forlexample, a machineiforpunching.accountingand statistical record :cards 'in vaccordancewith""-the well known twelve V.position 2-hole alphabeticalcombinational code. ,A `machine of .this `type :is disclosed in PatentNo. 1,976,618.

The alphabet in accountingandstatisticalfrecords cards is yrepresentedVby combinations fof holes inthe "0, 11, and 121indexfpoint.jpo sitions,respectively, .withtholes inthe 11 A.to .-9 index-point positions. Thus,the vletter A is represented by the combination 4of a ..12zhole and a 1hole punched in .5a single column/.of `the card. The wires W0 to WMin.-Fig.'5 may be connected to the .twelve"punchfselecting magnets of apunch such *as disclosed inthe aboveipatent so that the common brush-CB,:powerirolier PR, and the conductive Aplates 19h function to control'thepunch magnets Yin the above patent in the 4same way as the'card sensingbrushes do. For example, ywhen fthe :A key of lthe ltypewriter isdepressed, `'the `conductive plates '19h fortheh key will close a`circuit from the power roller PR to the wire W12 and also to the wireWI so'that current can flow `from the wire 'WI3 fthrough the .powerroller PR, lthe A lconductive vplates Hb to the wires 4W12 :and Wl andthence to :the 112 punch magnet and 'the 1 fpunch'magnet which willresult in punching the combination of a 12 hole and a l hole intheparticular column ofthe card which is in `register `with the punch.in the same general "fashion asa i12'brush `and a '1brush in the above.patent close circuits to :the punch magnets.

The conductive plates |911 for the'numerical keys of Athe typewriter'close only one circuit to the corresponding wires W0 to W9. Thus, ifthedigit l is printed, the operative .conductive plate AIilb.crn'responding4to 'the 1""ikey will 4cltise a `circuit to 'the wire Wfl and lthus.causefthe ."1" .punch magnet to operate. i,

It will be understood rthat wby 'applying solenoids to the .keys vil "ofa second typewriter, fit will be possible :for the first typewriter to'control the second typewriterlby direct circuits from the conductiveplates I9b of the iirstmac'hin'e to the solenoids operating thecorresponding. keys of the second typewriter. I

The foregoing are merely illustrative ways in which the machine may beusedin accordance with well-known needs. It will be understood that thecams I9 may be provided with more than two conductive plates 19h, ifnecessary, tb enable each cam to'close several circuits .or the cam maybe made whgpy .mtal

or with a metallic insert forming the entire tread so as to close asingle circuit.

The principal advantage of the foregoing sclective circuit closing meansis that it requiresvery few additional parts which is a distinctadvantage in a mechanism of this type because of the fact thattypewriting machines are usually internally crowded with the essentialparts of the typewriter mechanisms and it is seldom very convenient,when the power mechanism is designed for maximum eiciency, convenience,durability, and minimum cost, to apply auxiliary contacts withoutconsiderable additional mechanism. In the past, it has been found thatthe installation of this additional mechanism not only has been veryinconvenient and often made it necessary to enlarge the base of themachine, but the additional mechanism has imposed an additional load onthe power mechanism, thereby adversely affecting its operation.

In the present case, the springs 24 are the only additional parts whichmust be supplied to the type bar operating mechanisms to render thecircuit closing means eifective and these springs are so arranged thatthey are normally initially under a relatively slight tension which isrelaXed during the cycles of operation of the type bars and theretensioning of these springs when the type bars restore is very slightso as to irnpose no additional burden on the restoring springs I6 and 22which are greatly superior in strength to the springs 24. Furthermore,the springs 2li are disposed in such a relationship to the cams I9 thatthe eifect thereof on the cams I9 is so trilling as to have no eiect onthe force of the blow of the type bars.

An advantage of the mechanism is that good electrical contact is assuredsince the pressure between the conductive plates Mb and the power rollerPR naturally is quite heavy in View of the fact that the power roller PRoperates the power units I4 against the inertia of the parts comprisingthe power units and the type bars and against the tension of the springsI6 so that there should be no slippage of the treads of the cams I9 onthe power roller PR.. If such a slippage does occur, it will tend towardthe establishment of even better contact due to the wiping action whichby itself would be a distinct advantage, if it occurred.

It will thus be seen that not only is the contact closing means verypositive and reliable in its action, but the cost of installing it inthe machine is negligible in comparison with other arrangements wherethe machine is provided with a iixed bank of contacts with speciallyconstructed cams having extension arms, insulating pins, and the likefor operating the contacts. In such structures, the contact pressurenecessarily must be kept as low as possible, otherwise the type barmechanisms are likely to be excessively loaded and a disadvantage ofsuch mechanisrns is that it is very diilicult to adjust the springtension of all of the contact springs so that all ofthe power units areequally loaded. In the present case, there is no such problem as thereis nothing at all to adjust and the only vital reaction exerted on thepower unit is the normal reaction between the power actuator and thepower unit which is incidental to the operation of the type bar by powerin any case.

In the drawings, the contact elements |9b are shown as being coextensivewith the full length of the tread surface of the cam I9 on theassumption that it is desirable to maintain full contact throughout theentire period in which the cam I9 is in contact with the power rollerPR. It is possible to obtain relative timing between the plates ISb orcause these plates to individually close more than one circuit peroperation of the type bar. For example, the edges of the plates I9balong the tread could be cut away in such fashion that the actualclosing of the circuit is delayed or shortened, as desired. By cutting ashallow notch in the tread portion of the plates Ib of suitable length,as in Fig. 4, each plate may be caused to emit two electrical pulses ormore according to the number ,of notches lcut in the plate. Thus, themechanism is suitable for communication' systems in which each key mustcontrol the transmission of a series of impulses rather than a singleimpulse. Various other modifications of the plates |91) will occur tothose skilled in the art to adapt the circuit closing means to the needsof control business machines or printing telegraph receivers.

While there have been shown and described and pointed out thefundamental novel features of the invention as applied to a preferredembodiment, it will be understood that various omissions andsubstitutions and changes in the form and details of the deviceillustrated and in its operation may be made by those skilled in the artwithout departing from the spirit of the invention. It is the intention,therefore, to be limited only as indicated by the scope of the followingclaims.

What is claimed is:

l. In a power operated typewriter, character keys, type bars, acontinuously movable main power actuator having an electricallyconductive power driving surface and a series of power units havingdriven elements selectively coupled by said keys with said actuator foroperating the type bars selectively, said elements having electricallyconductive portions making electrical contact with said driving surfacewhile the type bars are being operated` by said actuator.

2. A power mechanism for typewriters and like machines comprising acontinuously movable main power actuator having a surface ofelectrically conductive material; normally inactive power units, eachfor operating a different instrumentality of the typewriter andincluding a normally disengaged driven element having an electricallyconductive portion engageable with said surface so as to close a circuitwhen the driven element is engaged with said actuator; and means toselectively engage said elements with said actuator.

3. In a machine of the class described, a continuously movable mainpower actuator having an electrically conductive driving surface, apower unit having an element engageable with said surface to enable saidpower unit to be operated by said actuator, one of said surface and saidelement being insulatably mounted so as to enable a circuit to be closedby contact therebetween only when said element is engaged with saidactuator, and means to elect driving engagement between said actuatorand said element.

4. In a typewriting machine, a printing device, a key representative ofsaid device, a main power roller having a driving surface ofelectrically conductive material, and a power unit having a mechanicalconnection to said printing device and including a cam elementengageable by said key with said power roller to actuate said printingdevice and making electrical connection with said 7 surf-ece, only whenthe power roller is actuating said powery unit.

5. Apower mechanism for typewriting and like machines comprising acontinuously movable moin power actuator having an electricallyconductive surface, a power unit having a biased inoperative position inwhich it is free of said actuator and an operative position in which itengages with said actuator` and including an element having anelectrical contact surface engaging said conductive surface when thepower unit is engaged with said actuator, and means to engage said powerunit with said actuator.

6. A power mechanism for typewriters and like machines comprising acontinuously movable main power actuator having an electricallyconductive surface, a power unit having a biased inoperative position inwhich it is free of said actuator and an operative position in which itengages with said actuator for operation by the latter and including anelement which is normally electrically insulated from said surface butarranged to make electrical contact with said surface to close anexternal circuit when said power unit is engaged with said actuator, and

means to cause said power unit to engage said actuator.

7. In a machine of the class described, a power roller having anelectrically conductive driving surface, a power unit comprising asub-lever mounted for rocking movement and a cam initially rotatable onsaid lever to engage the cam with said surface for subsequent driving bysaid roller, said cam having an electrically conductive portion making`electrical contact with said surface when said cam is driven by saidroller, and means to initially cause rotation of said cam.

8. In combination, a power roller having an electrically conductivesurface, a normally idle power unit having a cam rotatable by said powerroller and having electrical contact means making at least oneelectrical contact with said power roller surface when rotated by thelatter, and means to move the cam into rotatable engagement with thepower roller.

9,. In combination with a rotary power actuator having an electricallyconductive driving surface, a power unit having an element initiallymovable into engagement with` said actuator for rotation thereby andincluding electrical contact means operative to close a plurality ofseparate circuits by rolling contact with said rotary actuator, andmeans to enga-ge said element with said actuator.

A10. In combination, a continuously movable power actuator having anelectrically conductive surface, a normally idle actuated deviceincluding an element engageable with said actuator to enable the latterto actuate said device and including contact means arranged to make atleast one electrical contact with said surface during the period ofoperation of said device by said actuator.

1l. In a power operated typewriter, character keys, type bars, a mainpower actuator having an electrically conductive power driving surfaceand a series of power units having driven elements selectively coupledby said keys with said actuator for operating the type bars selectively,said elements having electrically conductive portions making rollingelectrical contact with said driving surface while the type bar-s arebeing op-` @rated by said. actuator.

12. In a power operated typewriter, character keys, type bars, a mainpower actuator having an electrically conductive power driving surfaceand a series of power units having driven elements selectively coupledby said keys with said actuator for operating the type bars selectively,said elements having electrically conductive portions making a pluralityof successive electrical contacts with said driving surface, while thetype bars are being operated by said actuator.

13. A powermechanism for typewriting and like machines comprising a mainpower actuator having an electrically conductive surface, a normallyidle power unit engageable with said actuator and including an elementhaving av contact element progressively engaging different successiveportions of said conductive surface when the power unit is engaged withsaid actuator, and means to engage said power unit with said actuator.

14. A power mechanism for typewriters and like machines comprising amain power actuator having an electrically conductive surface, anormally idle power unit engageable with said actuator for operation bythe latter and including an element which is normally electricallyinsulated from said surface but arranged to make rolling electricalcontact with said surface to close an external circuit when said powerunit is engaged with said actuator, and means to cause said power unitto engage said actuator.

l5. In combination. a power roller having an electrically conductivesurface, a normally idle` power unit having a cam rotatable by saidpower roller and having electrical contact means making at least onerolling electrical contact with said power roller when rotated by thelatter, and means to move the cam into rotatable engagement with thepower roller.

16. In combination, a rotary actuator having an electrically conductivedriving surface, a normally idle coupling element adapted for rotarydriven engagement with said actuator and having a contact elementelectrically contacting said driving surface for rotation thereby whenthe first element is engaged with the actuator, and means to engage saidcoupling element with said actuator.

17. In a power actuated mechanism having an initiating means and acorresponding part to be actuated, a continuously movable power actuatorhavingt an electrically conductive driving surface, and a power unitoperatively connected to move said corresponding part independently ofsaid initiating means and having an element movable into contact withsaid driving surface by said initiating means to actuate said part. saidelement having an electrically conductive portion engageable with saidsurface to close a circuit when the element is engaged with saidactuator.

EDWARD J. RABENDA.

References Cited in the ille of this patent UNITED STATES PATENTS

